GRAPHING LINES
PLOTTING POINTS 4/8/13
What is an ordered pair?Two numbersIn parentheses Separated by a commaLike this: (4, 2)
ORDERED PAIRSWhat do they mean?
Represent a point on a coordinate plane.
1st number is x.2nd number is y.(x, y)
THE COORDINATE PLANEUsed to plot points and graph lines
and other functions.x moves left and right.y moves up and down.Positive moves
right or up.Negative moves
left or down.
TO PLOT POINTS:Start at the origin
(the center of the graph)Move left or right first (using x)Then, move up or down (using y)Count spaces, not lines!
EXAMPLESPlot and label each ordered pair.A. (2, 4)B. (-3, 1)C. (5, -2)D. (-4, -3)
YOU TRY!Plot and label each ordered pair.A. (-1, 3)B. (5, -1)C. (4, 2)D. (-5, -4)
GRAPHING LINES (WITH A TABLE) 4/10/13When you are given a filled in table:
The x and y values make ordered pairsPlot each point on the graphThen, connect them with a straight lineUse a RULER! No messy lines!!
EXAMPLEx y-4 5-2 30 12 -14 -3
FILLING IN YOUR TABLEWhen you are given an equation:
Choose x values for the table. (Or, they may be given to you)
Plug each # into the equation for x and find y.
Fill those y-values in the table.Then, plot the points and
draw the line.
EXAMPLE
x y
y = 2x - 3
FINDING SLOPE (FROM A GRAPH)
4/16/13What is slope?
The steepness/slant of a line.Also called “rate of change”
Real life examples:Ski slopeWater slideWheelchair ramp
Bigger slope means steeper line!
4 TYPES OF SLOPES
TO COUNT SLOPE:Count between any two points on a line.Slope = rise runRise: how far up or down
Run: how far left or right
EXAMPLE:Find the slope of the line.
EXAMPLE:Find the slope of the line.
EXAMPLE:Find the slope of the line.
EXAMPLE:Find the slope of the line.
YOU TRY!Find the slope of the line.
FINDING SLOPE (FROM 2 POINTS)
4/17/13Remember: ordered pairs represent
points on a graph.So, we can find slope using 2 ordered
pairs: (x1, y1) and (x2, y2)An m is often used to mean slope.
m = rise = change in y = y2 – y1
run change in x x2 – x1
SLOPE SONG(S)http://
www.youtube.com/watch?v=O3Yw6bGCM3c
http://www.youtube.com/watch?feature=player_detailpage&v=8TFf-p2cE70
EXAMPLES:Find the slope between each set of
points.(3, 4) and (5, 1)
(-3, 6) and (2, 6)
(4, 2) and (4, -3)
YOU TRY!Find the slope between:(7, 3) and (5, -1)
(6, 2) and (6, -2)
Top Related